Fabric Director and Fabric Elements

The Fabric Director monitors the InfiniBand fabric by polling the nodes or elements
of the fabric. Each fabric element has a Fabric Director instance, and the
two communicate with eachother in a one-to-one relationship. The Fabric Director gathers information about
the fabric element through the LDA and ENVD daemons running on the fabric
element. From the information gathered, the Fabric Director creates a local SNMP fabricMIB.

One Fabric Director is assigned the role of master. The master Fabric Director
gathers information about all of the fabric elements by communicating out-of-band (management network)
with the Fabric Directors instances on those fabric elements. This master Fabric Director creates
a model of the fabric which is also in the form of an
SNMP MIB, as defined by the SUN-FABRIC-MIB specification.

By default, Fabric Directors run in non-master mode. Only when a Fabric Director
reads the fabric node list and discovers that its respective fabric element is
to host the master Fabric Director, does it become the master Fabric Director.